An online database of architectural and historical information and images for 35,000+ structures, 110,000 images+ images and maps and biographies of 5,000+ architects in the 5 county region around Philadelphia. Development was a collaboration between private, academic, and public entities led by the Athenæum of Philadelphia.

Founded as William Penn's "Holy Experiment," Philadelphia has a centuries-long history of fostering and constructing prominent houses of worship throughout the city. In recent decades, as congregations face declining membership and shifting neighborhood demographics, these historically- and architecturally-significant properties have often suffered from deferred maintenance, insensitive alterations, and partial or complete demolition. Advocacy organizations like the Preservation Alliance for Greater Philadelphia and Partners for Sacred Places have focused on this issue for years, highlighting the threats to Philadelphia's neighborhoods and communities if these structures continue to be abandoned or lost. Over the summer of 2011, in order to more fully understand and address the issue, the Preservation Alliance partnered with Philadelphia Historical Commission and Partners for Sacred Places to develop a comprehensive index of historic churches covering the entire city. Compiling, verifying, and updating data from a number of different sources, University of Pennsylvania graduate student Molly Lester assembled a database which includes every purpose-built house of worship constructed in the city before 1960. Data elements include: current congregation, original congregation, address, year of construction, original architect and whether or not the build is on the Philadelphia or National Historic Registers.

To map older streets with historical value in the City of Philadelphia.

The City of Philadelphia made a major revision of the zoning code and base maps in 2012. These shapefiles provide a few historic versions of zoning data up to the time of the zoning code change.

These ESRI shape files are of National Park Service tract and boundary data that was created by the Land Resources Division. Tracts are numbered and created by the regional cartographic staff at the Land Resources Program Centers and are associated to the Land Status Maps. This data should be used to display properties that NPS owns and properties that NPS may have some type of interest such as scenic easements or right of ways.

City of Philadelphia land use as ascribed to individual parcel boundaries or units of land. Land use is the type of activity occurring on the land such as residential, commercial or industrial. Each unit of land is assigned one of nine major classifications of land use (2-digit code), and where possible a more narrowly defined sub-classification (3-digit code). The land use feature class has been field checked and corrected for the following Planning Districts.

Pittsburgh Historic Districts

This EnviroAtlas dataset portrays the total number of historic places located within each Census Block Group (CBG). The historic places data were compiled from the National Register of Historic Places, which provides official federal lists of districts, sites, buildings, structures and objects significant to American history, architecture, archeology, engineering, and culture. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

A mapped dataset and layer of sites and districts identified in the Locational Atlas and Inventory of Historic Sites in Montgomery County, Maryland. The Location Atlas is a list resources that are potentially historic. Resources listed in the Atlas are protected from demolition or "substantial alteration" under Chapter 24A of the County Code. For more information, see http://montgomeryplanning.org/historic/research.shtm. Source: M-NCPPC Planning. https://montgomeryplans.org/arcgis/rest/services/Overlays/HistoricPres_LA_Sites_and_Districts/MapServer/0

A mapped dataset and layer of individual sites and districts that the County has designated as historic, or which have been listed in the National Register of Historic Places. The National Register is the federal list of buildings, districts, and other objects significant to the nation’s history or architecture. For more information, see http://www.nps.gov/nr/faq.htm#nr. The Master Plan for Historic Preservation is the County's preservation planning document that includes the list of all county-designated historic sites and districts. Sites and districts which have been added to the Master Plan have been found to be of special historic or architectural significance and receive protection under the Historic Preservation Ordinance, Chapter 24A of the County Code. For more information, see http://montgomeryplanning.org/historic/research.shtm. For field descriptions, see attachment on the About tab. Source: M-NCPPC Planning